Fix unreachable ES url exception

EE: true
Changelog: fixed

ee/lib/gitlab/elastic/client.rb

@@ -7,12 +7,19 @@ module Gitlab
     module Client
       extend Gitlab::Utils::StrongMemoize
 
+      OPEN_TIMEOUT = 5
+
       # Takes a hash as returned by `ApplicationSetting#elasticsearch_config`,
       # and configures itself based on those parameters
       def self.build(config)
         base_config = {
           urls: config[:url],
-          request_timeout: config[:client_request_timeout],
+          transport_options: {
+            request: {
+              timeout: config[:client_request_timeout],
+              open_timeout: OPEN_TIMEOUT
+            }
+          },
           randomize_hosts: true,
           retry_on_failure: true
         }.compact

ee/spec/lib/ee/gitlab/elastic/helper_spec.rb

@@ -18,7 +18,7 @@ RSpec.describe Gitlab::Elastic::Helper, :request_store do
   end
 
   after do
-    helper.delete_index(index_name: @index_name)
+    helper.delete_index(index_name: @index_name) if @index_name
   end
 
   describe '.new' do

ee/spec/lib/gitlab/elastic/client_spec.rb

@@ -18,14 +18,18 @@ RSpec.describe Gitlab::Elastic::Client do
       end
 
       it 'does not set request timeout in transport' do
-        expect(client.transport.options).not_to include(:request_timeout)
+        options = client.transport.options.dig(:transport_options, :request)
+
+        expect(options).to include(open_timeout: described_class::OPEN_TIMEOUT, timeout: nil)
       end
 
       context 'with client_request_timeout in config' do
         let(:params) { { url: 'http://dummy-elastic:9200', client_request_timeout: 30 } }
 
-        it 'does not set request timeout in transport' do
-          expect(client.transport.options).to include(request_timeout: 30)
+        it 'sets request timeout in transport' do
+          options = client.transport.options.dig(:transport_options, :request)
+
+          expect(options).to include(open_timeout: described_class::OPEN_TIMEOUT, timeout: 30)
         end
       end
     end